Vehicle seat with a support for the lower legs

ABSTRACT

The invention relates to a vehicle seat ( 1 ) having an automatically displaceable lower leg support ( 3 ). The lower leg support can be displaced in an automatically driven fashion between a stowaway position and a position of use.  
     In order to obtain a compact design of the vehicle seat and a high degree of protection against impact operation, the lower leg support ( 3 ) has a sensor ( 6, 61, 62 ) which is connected to a control device ( 52 ) of the drive ( 5 ). The sensor ( 6 ) is designed to detect an obstacle.

FIELD OF THE INVENTION

The present invention relates to a vehicle seat.

BACKGROUND INFORMATION

German Published Utility Model No. 92 00 777.5 describes a bus seat witha footrest. The footrest is coupled to the seat cushion of the bus seatvia a parallelogram linkage. A pneumatic spring interacts with theparallelogram linkage in order to fold the footrest from a stowawayposition arranged underneath the seat cushion into a position of use.

German Published Patent Application No. 39 10 778 describes a controldevice for the backrest of a seat. The control device controls anactuator device which adjusts the inclination of the backrest of a seat.This control device detects an obstacle as the backrest of the seatinclines, it stops the inclination movement of the backrest of the seat.

SUMMARY

An example embodiment of the present invention may provide a vehicleseat with an adjustable lower leg support which may have a compactdesign, may have a comfortable sitting position and may be easy and safeto operate. The vehicle seat may have a high degree of protectionagainst incorrect operation.

The lower leg support of the vehicle seat has an automatic drive. Acontrol device with a sensor is connected to the drive in order tocontrol the lower leg support. The sensor is designed to detect anobstacle. As a result, trapping and/or damage and/or the risk of injuryas the lower leg support is automatically adjusted, or when incorrectoperation is carried out, is at least partially reduced or entirelyprevented.

The drive is designed to adjust the lower leg support automatically,e.g., in an infinitely variable fashion, e.g., in order to displace thelower leg support from a space-saving stowaway position into a positionof use and/or from a position of use into the stowaway position. It isalso possible to adjust and/or set the sitting position as desired usingthe drive. The stowaway position is arranged closely against the seat sothe vehicle seat may take up as little overall space as possible. Thecontrol device may be designed such that it detects the stowawayposition of the lower leg support as a zero position, which serves asthe reference position for determining the travel of the lower legsupport. In the position of use, the lower leg support is pivoted intothe foot well and forms a comfortable rest and/or support for the lowerlegs and/or the feet of the sitting person. The control devicecalculates the position of the lower leg support in the position of useby the pivoting angle and/or the displacement travel.

In an example embodiment, the lower leg support is pivoted by the driveabout a pivot axis which extends transversely with respect to thevehicle seat. In addition, the length of the lower leg support may bevaried, e.g., the area on which the lower legs rest may be increased bylengthening the lower leg support. During this adjustment process, thelower leg support may strike an obstacle, for example, a piece ofluggage or the feet of a sitting person. In order to prevent theobstacle becoming trapped, and/or the lower leg support and/or theobstacle being damaged, the sensor is arranged at the free end of thelower leg support.

The sensor may be arranged as a proximity sensor, e.g., an inductive orcapacitive proximity sensor and/or as a pressure sensor, e.g., as apiezoelement and/or switch panel. When an obstacle is struck and/ordetected, the sensor transmits a signal to the control device.

In an example embodiment, provision is made for the control device tostop the drive if the sensor detects an obstacle. However, it is alsopossible for the control device to stop the drive and/or at leastpartially reverse it in order to prevent the lower leg support and/orthe obstacle from being trapped and/or damaged.

The sensor may also be arranged to determine the maximum possibledisplacement travel of the lower leg support. For this purpose, byactuating the drive, the control device moves the lower leg support outuntil it arrives at a limit position, i.e., abutting againstinstallations in the vehicle or seats. The sensor detects this limitposition so that the control device may detect and/or store the maximumpossible adjustment travel of the lower leg support. As a result, e.g.,tolerances between the arrangements in the vehicle or installations inthe vehicle and the displacement travel and/or the dimensions of thelower leg support may be sensed and compensated for. The sensor detectsthe set position with the largest possible displacement travel and thuslimits the displacement travel in this limit position.

It is possible to use the vehicle seat in passenger cars, buses andwatercraft or rail vehicles, etc. The vehicle seat may also be providedas a comfortable passenger seat in aircraft.

According to an example embodiment of the present invention, a vehicleseat includes: an adjustable lower leg support; a drive configured toautomatically adjust the lower leg support between a stowaway positionand a position of use, and a control device configured to control thedrive. The control device includes a sensor arranged on the lower legsupport configured to detect an obstacle.

The sensor may be configured as at least one of (a) a proximity sensorand (b) a pressure sensor.

The drive may be configured to adjust at least one of (a) a length and(b) an inclination of the lower leg support.

The drive may be configured as one of (a) an electrical drive and (b) apneumatic drive.

The lower leg support may include an enclosed lower leg support surface.

The drive may be configured to at least one of (a) increase and (b)decrease the lower leg support surface.

The lower leg support may include a freely displaceable end and an endpivotably mounted on one of (a) a seat cushion and (b) a seat frame, andthe sensor may be arranged at the freely displaceable end of the lowerleg support.

The sensor may include two detection regions.

The sensor may include a first detection region arranged on a rear ofthe lower leg support and a second detection region arranged on an endside of the lower leg support.

One of (a) the first detection region and (b) the second detectionregion may be configured to detect an obstacle when the lower legsupport pivots.

One of (a) the first detection region and (b) the second detectionregion may be configured to detect an obstacle when the lower legsupport is extended.

The sensor may include a bar arranged to cover and connect the firstdetection region and the second detection region, and the bar may beconfigured to distribute pressure, that occurs when an obstacle isstruck, between the first sensor region and the second sensor region.

The control device may be configured to at least one of (a) stop and (b)reverse the drive in accordance with detection of an obstacle.

According to an example embodiment of the present invention, a vehicleseat includes adjustable lower leg support means, drive means forautomatically adjusting the lower leg support means between a stowawayposition and a position of use, and control means for controlling thedrive. The control means includes sensing means arranged on the lowerleg support and for detecting an obstacle.

Further features and example embodiments of the present invention aredescribed below with reference to the appended Figures. The features andfeature combinations which are mentioned above and described below maybe used not only in the respectively stated combination but also inother combinations or alone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of the vehicle seat with the lower leg support in aposition of use.

FIG. 2 is a cross-sectional view of the lower leg support in a stowawayposition.

FIG. 3 is a schematic view of the arrangement of the lower leg support.

FIG. 4 is a cross-sectional view of the sensor.

DETAILED DESCRIPTION

FIG. 1 illustrates a vehicle seat 1. It has a backrest 11 with headrest12 and a seat cushion 2 with lower leg support 3. The vehicle seat 1 isdisplaceably mounted by rails 14 in a vehicle, for example, in the rearof a passenger car. A seatbelt mount 13 for a three-point belt isintegrated into the backrest 11. The backrest 11 and the seat cushion 2each have an upholstered element with a covering material, for example,leather. The upholstered element 21 upholsters the seat cushion 2 andthe lower leg support 3 and is of continuous design. It forms, on itsupper side, a coherent, upholstered sitting surface which extends fromthe seat cushion 2 as far as the lower leg support 3.

The lower leg support 3 is extended forward in the position of rest orposition of use which is illustrated in FIG. 1. It has been pivoted upin the forward direction and extended in order to enlarge its restingsurface for the lower legs. The lower leg support 3 has athree-component telescopic component with an upper telescopic element32, a central telescopic element 33 and a lower telescopic element 34.In order to vary the length of the lower leg support 3, the telescopicelements 32, 33 and 34 may be adjusted in a telescopic fashion by anelectric drive 5. A footrest 4 is arranged at the lower end of the lowerleg support 3. It is connected to the lower telescopic element 34 andhas a footplate 41 which is mounted on a crossmember 42 and which isfolded out into the position of use and provides a comfortable supportfor the feet. The footplate 41 may be pivoted about an axis of rotationwhich extends transversely with respect to the lower leg support 3, andin the position of use it is approximately perpendicular to the lowerleg support 3. One end of the lower leg support 3 is connected to theseat cushion 2. The inclination of the lower leg support 3 in relationto the seat cushion 2 may be set by an inclination adjuster 35 with anelectric drive motor. The other end of the lower leg support is freelydisplaceable and supports the footrest 4. A sensor 6 for detectingobstacles in the displacement path of the lower leg support 3 isarranged at the free end.

The vehicle seat 1 has both the position of rest or lying positionillustrated in FIG. 1 and further sitting positions, e.g., also anupright sitting position with retracted lower leg support 3 and afolded-in footrest 4.

The stowaway position with retracted lower leg support 3 and folded-infootrest 4 is illustrated in FIG. 2. The telescopic elements 32, 33 and34 of the lower leg support 3 are pushed one into the other and arearranged pointing approximately vertically downwardly at the front endof the seat cushion 2. An inclination adjuster 35, which connects thelower leg support 3 to the seat cushion 2, is arranged on the uppertelescopic element 32. The inclination adjuster 35 has an electric motorfor adjusting the inclination of the lower leg support 3.

The footplate 41 is arranged in parallel with the lower leg support 3and forms, together with the seat upholstered element 21, a planar frontsurface which closes off the vehicle seat from the front. The rear ofthe footplate 41 is flush with the upper side of the seat upholsteredelement 21 so that the vehicle seat does not have any protruding edgesand/or the footplate 41 may not be inadvertently folded forward. In thestowaway position, the lower leg support 3 and the footrest 4 arearranged resting against the front region of the seat cushion 2. Thisstowaway position may save space and may not adversely affect the amountof foot space available in the vehicle.

The sensor 6 is arranged at the lower end of the lower leg support 3 andhas two sensor surfaces 61, 62. The first sensor surface is arranged onthe end side of the lower leg support 3 and is arranged to detectobstacles which are in its displacement path when the lower leg support3 extends in a linear fashion. The second sensor surface 62 is arrangedat the rear of the lower leg support 3, i.e., on the side facing awayfrom the lower leg support surface. It is arranged to detect obstacleswhich are in the displacement path when the lower leg support 3 ispivoted.

FIG. 3 illustrates the schematic design of lower leg support 3 withdrive 5. The drive 5 is arranged as a spindle drive and has an electricdrive motor 51 which drives a first spindle drive 56 and a secondspindle drive 57. The drive 5 is connected via a bridge to the centraltelescopic element 33. The first spindle drive 56 engages between thecentral telescopic element 33 and the upper telescopic element 32, andthe second spindle drive 57 engages between the central telescopicelement 33 and the lower telescopic element 34. The upper telescopicelement 32 and the lower telescopic element 34 are moved synchronouslyaway from the central telescopic element 33 or toward the centraltelescopic element 33 via the spindle drive 56, 57.

The electric drive motor 51 drives the first spindle drive 56 and thesecond spindle drive 57 in opposite directions by a gear mechanism. As aresult, the electric motor 51 drives the telescopic elements 32, 33, 34such that, in one sense of rotation, the upper telescopic element 32 andthe lower telescopic element 34 are driven away from the centraltelescopic element 33, and in the opposite sense of rotation, the uppertelescopic element 32 and the lower telescopic element 34 are driventoward the central telescopic element 33.

The drive motor 51 is connected to a control device 52. The controldevice 52 controls the drive motor 51 and/or the inclination adjuster 35and thus the movement sequence of the lower leg support 3. The controldevice 51 is connected to the sensor 6 in order to detect obstacles, thesensor 6 being arranged at the lower end of the lower leg support 3. Thecontrol device 52 is connected via cables to the sensor 6 and inaddition to the drive motor 51 and the inclination adjuster 35. Inaddition, the control device 52 has a power feed line. A cable guide 53which is connected to the central telescopic element 33 prevents thecables becoming entangled and/or damaged when the lower leg support 3moves. The cable guide 53 has a spring-loaded cable drum whichautomatically retracts or unrolls the guided cables. The cable guide 53therefore takes up the cable slack and keeps the cables taut so that thecables are prevented from becoming entangled and/or flapping around.

If the sensor 6 detects an obstacle, it transmits a signal to thecontrol device 62. The latter then stops the movement of the lower legsupport 3 and moves it back a certain amount in order to prevent theobstacle from becoming trapped and/or being damaged.

FIG. 4 illustrates the sensor 6. It is arranged on the crossmember 42 ofthe lower telescopic element 34. A first sensor surface 61 is arrangedon the end surface and a second sensor surface 62 is arranged at therear of the crossmember 42. The sensor surfaces 61, 62 extend over alarge part of the width of the lower leg support 3 and are arranged aspressure-sensitive switch panels.

The sensor 6 has an electrically conductive contact film 65 which isconnected in a planar fashion to the crossmember 42 via an insulator 64.An electrically conductive connecting strip 66 is arranged over foaminlays 67 which are arranged as spacing elements and are at a distancefrom the contact strip 65. If pressure is exerted on the connectingstrip 66, the foam inlay 67 is pushed over and the connecting strip 66moves into electrically conductive contact with the contact strip 65.

An elastic rubber strip 63 covers the first switching surface 61 and thesecond switching surface 62. The rubber strip 63 is clipped to thecrossmember 42 and secures the sensor 6 so that it rests directly on thecrossmember 42. The rubber strip is connected to the sensor 6 so that,in order to replace the sensor 6, only the rubber strip 63 with sensor 6has to be replaced.

The elasticity of the rubber strip 63 may be dimensioned such that, whenthere is contact with an obstacle, it distributes the pressure whichoccurs between the first sensor surface 61 and the second sensor surface62. As a result, the obstacle may be reliably detected even if theobstacle does not directly strike the first sensor surface 61 or thesecond sensor surface 62.

In the stowaway position, the sensor 6 abuts against the vehicle seat 1.As a result, the sensor 6 detects the home position of the lower legsupport 3. The home position thus serves as a reference position for thecontrol device 52, from which position it determines the position of thelower leg support over the displacement travel. In order to compensatefor tolerances, the control device may determine the limit position ofthe lower leg support 3 by moving out the lower leg support to a maximumextent until the lower leg support moves into contact with installationsin the vehicle, and the sensor 6 signals the limit position. The sensor6 detects the maximum possible displacement position and thus limits themaximum possible displacement travel of the lower leg support 3.

1-10. (canceled)
 11. A vehicle seat, comprising: an adjustable lower legsupport; a drive configured to automatically adjust the lower legsupport between a stowaway position and a position of use; and a controldevice configured to control the drive, the control device including asensor arranged on the lower leg support configured to detect anobstacle.
 12. The vehicle seat according to claim 11, wherein the sensoris configured as at least one of (a) a proximity sensor and (b) apressure sensor.
 13. The vehicle seat according to claim 11, wherein thedrive is configured to adjust at least one of (a) a length and (b) aninclination of the lower leg support.
 14. The vehicle seat according toclaim 11, wherein the drive is configured as one of (a) an electricaldrive and (b) a pneumatic drive.
 15. The vehicle seat according to claim11, wherein the lower leg support includes an enclosed lower leg supportsurface.
 16. The vehicle seat according to claim 15, wherein the driveis configured to at least one of (a) increase and (b) decrease the lowerleg support surface.
 17. The vehicle seat according to claim 11, whereinthe lower leg support includes a freely displaceable end and an endpivotably mounted on one of (a) a seat cushion and (b) a seat frame, thesensor arranged at the freely displaceable end of the lower leg support.18. The vehicle seat according to claim 17, wherein the sensor includestwo detection regions.
 19. The vehicle seat according to claim 17,wherein the sensor includes a first detection region arranged on a rearof the lower leg support and a second detection region arranged on anend side of the lower leg support.
 20. The vehicle seat according toclaim 19, wherein one of (a) the first detection region and (b) thesecond detection region is configured to detect an obstacle when thelower leg support pivots.
 21. The vehicle seat according to claim 19,wherein one of (a) the first detection region and (b) the seconddetection region is configured to detect an obstacle when the lower legsupport is extended.
 22. The vehicle seat according to claim 20, whereinanother one of (a) the first detection region and (b) the seconddetection region is configured to detect an obstacle when the lower legsupport is extended.
 23. The vehicle seat according to claim 19, whereinthe sensor includes a bar arranged to cover and connect the firstdetection region and the second detection region, the bar configured todistribute pressure, that occurs when an obstacle is struck, between thefirst sensor region and the second sensor region.
 24. The vehicle seataccording to claim 11, wherein the control device is configured to atleast one of (a) stop and (b) reverse the drive in accordance withdetection of an obstacle.
 25. A vehicle seat, comprising: adjustablelower leg support means; drive means for automatically adjusting thelower leg support means between a stowaway position and a position ofuse; and control means for controlling the drive, the control meansincluding sensing means arranged on the lower leg support and fordetecting an obstacle.